Terragenesis has a nice article on casting bunkers in plaster from chocolate boxes.
Terragenesis has an article on building laboratory equipment for mad scientists. The photos show an amazing use of various household and electronics bits.
Tim’s Wargaming Blog has a photo tutorial on making “36 Miles of Barbed Wire.”
The Hawgleg site has a tutorial on using Amazing Mold Putty and Amazing Casting Resin to make models. The two products are available at stores like Hobby Lobby
This is a great video on modeling an abandoned farmhouse or shack for your wargames table.